[alfa] Re: Exh temps

[Jon Pike <jhpike@xxxxxxx>]

To clarify things as to my current conditions when I started measuring 
the exhaust temp..  I had already changed my timing to be at the M mark 
(on my pulley, supposedly 33deg) at max advance,  and had made the trip 
back to my friendly owner of a exhaust analyzer to tweak at my Spica... 
most recent bump was after moving my barometric capsule so I'd be 
resting on the 7th rather than 8th notch.  Mixture moved down from 3% CO 
to 1-1.5% (kinda hard to tell).  That's where I started measuring.

Other variables.. I'm measuring in the front cavity of the cat.. careful 
to not touch metal or ceramic,  so there's a long stretch of manifold 
and downpipe, though 77's had a rudimentary heat shield/insulator on the 
pipes to up the temp/keep driver cooler, there's got to be some cooling 
going on..  As well as heat from the cat..  I take it that normally you 
try to be much closer to the exhaust ports..

I'll know better if I ever get the O2 sensor together.. the kit I was 
going to order is now imminently going to release a improved model for 
possibly the same price.. some unknown time in the near future..  Almost 
ordered last night.. now I should wait..  
I'm noticing another strange phenomena.. my #1 plug is very clean.. 
insulator white as the driven snow.. while the other three are a light 
greyish white.  Makes me wonder if one is running leaner than the 
others, and why?  Haven't noticed up to this point.. maybe I'm leaner to 
the point that the difference makes a bigger appearance difference now.  
Will look for vacumm leaks, etc..  Have the dist vac point switch port 
there, but think it's securely capped off. (famous last words)  If so, I 
can imagine that my mixture readings are off..

I will talk distributor issues on the forking subject of Timing that has 
come up.. sounds like a worthy topic of its own..

Jon


> Jon
> I would not worry about 1300F what so ever.  Like Peter says, 1500F is a good
> bogey for an Alfa- we run up to 1650, and are trying to go up to 1800- all in
> the name of fuel economy.
>
> The distributor- that is another post.  Before going and getting whatever new
> distributior, check over your modifications- more than likely, the people who
> will sell you the modified distributor have one curved for that exact set up. 
> Or at least something close.  My friend John Hoard got one for his 1750 GTA,
> and he loves it!  
> But your retarted timing isn't causing any serious exh temp problems....  Even
> at 11.5:1, one can get 1550F- been there, done that.
>
> Eric Storhok
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